1. Field of the Invention
The present invention relates generally to die materials used in the preparation of refractory castings, and particularly to such a material which, when mixed with a liquid binder, provides an easy flow, quick-setting castable ceramic slurry composition.
2. Background Information
Dry blends for use in the preparation of high temperature castable compositions are known from, for example, U.S. Pat. Nos. 2,209,035 to E. M. Prosen and 3,649,732 to K. Brigham et al. The known compositions generally include di-hydrated ammonium phosphate mixed with silica or glass, and magnesium oxide.
The prior compositions, however, required relatively long time periods for setting of typically from 20 to 30 minutes. Moreover, in actual practice with such prior compositions, the finished casting cannot be removed from a mold for a minimum of one hour, followed by a slow firing schedule (typically 200.degree. F./hour to 1800.degree. F.) to produce maximum strength for the casting.